From: Dan Williams dan.j.williams@intel.com
mainline inclusion from mainline-v5.1-rc1 commit 21c75763a3ae18679e5c4e2260aa9379b073566b category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I47H3V CVE: NA
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commit 21c75763a3ae18679e5c4e2260aa9379b073566b upstream.
The target-node attribute is the Linux numa-node that a device-dax instance may create when it is online. Prior to being online the device's 'numa_node' property reflects the closest online cpu node which is the typical expectation of a device 'numa_node'. Once it is online it becomes its own distinct numa node, i.e. 'target_node'.
Export the 'target_node' property to give userspace tooling the ability to predict the effective numa-node from a device-dax instance configured to provide 'System RAM' capacity.
Cc: Vishal Verma vishal.l.verma@intel.com Reported-by: Dave Hansen dave.hansen@linux.intel.com Signed-off-by: Dan Williams dan.j.williams@intel.com Signed-off-by: Fan Du fan.du@intel.com Signed-off-by: Jackie Liu liuyun01@kylinos.cn Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Reviewed-by: Xie XiuQi xiexiuqi@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- drivers/dax/bus.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index a410154d75fb..28c3324271ac 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -279,13 +279,41 @@ static ssize_t size_show(struct device *dev, } static DEVICE_ATTR_RO(size);
+static int dev_dax_target_node(struct dev_dax *dev_dax) +{ + struct dax_region *dax_region = dev_dax->region; + + return dax_region->target_node; +} + +static ssize_t target_node_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct dev_dax *dev_dax = to_dev_dax(dev); + + return sprintf(buf, "%d\n", dev_dax_target_node(dev_dax)); +} +static DEVICE_ATTR_RO(target_node); + +static umode_t dev_dax_visible(struct kobject *kobj, struct attribute *a, int n) +{ + struct device *dev = container_of(kobj, struct device, kobj); + struct dev_dax *dev_dax = to_dev_dax(dev); + + if (a == &dev_attr_target_node.attr && dev_dax_target_node(dev_dax) < 0) + return 0; + return a->mode; +} + static struct attribute *dev_dax_attributes[] = { &dev_attr_size.attr, + &dev_attr_target_node.attr, NULL, };
static const struct attribute_group dev_dax_attribute_group = { .attrs = dev_dax_attributes, + .is_visible = dev_dax_visible, };
static const struct attribute_group *dax_attribute_groups[] = {